path: root/lib/CodeGen/MachineTraceMetrics.cpp

//===- lib/CodeGen/MachineTraceMetrics.cpp ----------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#define DEBUG_TYPE "machine-trace-metrics"
#include "MachineTraceMetrics.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/MC/MCInstrItineraries.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/ADT/SparseSet.h"

using namespace llvm;

char MachineTraceMetrics::ID = 0;
char &llvm::MachineTraceMetricsID = MachineTraceMetrics::ID;

INITIALIZE_PASS_BEGIN(MachineTraceMetrics,
                  "machine-trace-metrics", "Machine Trace Metrics", false, true)
INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo)
INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
INITIALIZE_PASS_END(MachineTraceMetrics,
                  "machine-trace-metrics", "Machine Trace Metrics", false, true)

MachineTraceMetrics::MachineTraceMetrics()
  : MachineFunctionPass(ID), MF(0), TII(0), TRI(0), MRI(0), Loops(0) {
  std::fill(Ensembles, array_endof(Ensembles), (Ensemble*)0);
}

void MachineTraceMetrics::getAnalysisUsage(AnalysisUsage &AU) const {
  AU.setPreservesAll();
  AU.addRequired<MachineBranchProbabilityInfo>();
  AU.addRequired<MachineLoopInfo>();
  MachineFunctionPass::getAnalysisUsage(AU);
}

bool MachineTraceMetrics::runOnMachineFunction(MachineFunction &Func) {
  MF = &Func;
  TII = MF->getTarget().getInstrInfo();
  TRI = MF->getTarget().getRegisterInfo();
  ItinData = MF->getTarget().getInstrItineraryData();
  MRI = &MF->getRegInfo();
  Loops = &getAnalysis<MachineLoopInfo>();
  BlockInfo.resize(MF->getNumBlockIDs());
  return false;
}

void MachineTraceMetrics::releaseMemory() {
  MF = 0;
  BlockInfo.clear();
  for (unsigned i = 0; i != TS_NumStrategies; ++i) {
    delete Ensembles[i];
    Ensembles[i] = 0;
  }
}

//===----------------------------------------------------------------------===//
//                          Fixed block information
//===----------------------------------------------------------------------===//
//
// The number of instructions in a basic block and the CPU resources used by
// those instructions don't depend on any given trace strategy.

/// Compute the resource usage in basic block MBB.
const MachineTraceMetrics::FixedBlockInfo*
MachineTraceMetrics::getResources(const MachineBasicBlock *MBB) {
  assert(MBB && "No basic block");
  FixedBlockInfo *FBI = &BlockInfo[MBB->getNumber()];
  if (FBI->hasResources())
    return FBI;

  // Compute resource usage in the block.
  // FIXME: Compute per-functional unit counts.
  FBI->HasCalls = false;
  unsigned InstrCount = 0;
  for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
       I != E; ++I) {
    const MachineInstr *MI = I;
    if (MI->isTransient())
      continue;
    ++InstrCount;
    if (MI-&g